Propelling mechanism for rotatably adjustable machines



N. A. WRIGHT ,836,056

PROPELLING MECHANISM FOR ROTATABLY ADJUSTABLE MACHINES Dec. 15, 1931.

Filed April 12, 1930 3 Sheets-Sheet INVE N TO R Harman filzfrz'gbf ATTORNEYS Dec. 15, 1931.

N. A. WRIGHT 1,836,056

PROPELLING MECHANISM FOR ROTATABLY ADJUSTABLE MACHINES Filed April 12, 1930 3 Sheets-Sheet 2 INVENTOR Harman IZZLZI'I'ghi ATTORNEYS Dec. 15, 1931. N. A. WRIGHT 1,836,056

PROPELLING MECHANISM FOR ROTATABLY ADJUSTABLE MACHINES Filed April 12, 1930 3 Sheets-Shet 3.

INVENTOR Harman 12212717152 ATTO RN EYS Patented Dec. 15, 1931 UNITED STATES PATENT OFFICE NORMAN A. WRIGHT, OF PONTIAC, MICHIGAN, ASSIGNOR TO PONTIAC TRACTOR COM- PANY, OF PONTIAC, MICHIGAN, A CORPORATION OF MICHIGAN PBOPELLING MECHANISM FOR ROTATABLY ADJ USTABLE-MACHINES Application filed .Ap'ril 12,

The present invention pertains to a novel portable machine, such as a heavy duty excavator, adapted to move from place to place under itsown power.

The principal object of the invention is to provide a device of this character wherein a simplified system of gearing is employed for turning the main platform on a pivot. ln present constructions a heavy central vertical shaft with a main gear thereon is provided for, this purpose, in conjunction with numerous other reducing gears and an intricate gear arrangement for driving the traction device. 3 Moreover, some of these gears carry parts of the weight of the super structure.

The matter of gearing is considerably simplified in the present invention by using a central main gear supported on a non-rotatable base structure. Associated with the ring gear is a concentric circular track which supports the carriage and the super structure by means of rollers. The carriage carries a transverse countershaft having a pair of gears riding on the ring gear. The eounterslnift is geared to the power plant, and by means of selective clutches on the counter-shaft cooperating with the gears in mesh with the ring ear, the carriage may be caused to turn in either direction at will.

The invention further includes a pair of traction gears mounted loosely on the eountershaft and operatively connected to the parallel sides of a bilateral traction system. The traction gears may be separately locked to the shaft by means of selective clutches to steer the machine, or locked sinnultaneously to propel the machine in a straight line.

The invention is fully disclosed by way of example in the following description and in the accompanying drawings, in which Figure 1 is a longitudinal section of the machine, partly in elevation Fig. 2 is a vertical section on the line 22 of Fig. 1, and

Fig. 3 is a plan section below the working platform.

Reference to these views will now be made by use of like characters which are employed 1930. Serial No. 443,886.

to designate corresponding parts throughout. 4

The traction device on which the machine is ultimately supported includes a pair of parallel frames 1 equipped at their ends with stub shafts 2 carrying sprocket wheels 3. Endless traction members 4 are trained over each pair of aligned sprocket wheels 3 in a. manner well known in the art. The frame members 1 are reduced somewhat in height at substantially the mid portions thereof, as indicated by the dotted line 5 in Figure 1, for a purpose which will presently appear.

The base structure of the machine includes a pair of I-beams 6 lying transversely of the frames 1 and secured thereto by means of brackets 7, thereby fixing the frames in a permanent parallel relation. I-beams is held a base ring 8 having radial spokes 9 and a vertical bearing 10 at the center thereof.

Upon the spokes of the ring 8 is secured a bevel ring gear 11 having an outward flange 12 which constitutes a track as will presently appear. Another ring member or carriage 13 with radial spokes 14 is supported on the track by means of rollers 15 journalled on certain of the spokes-and riding on the track. At the center of the ring 13 is formed a hub member 16 extending into the bearing 10 and flared outwardly at its lower end as at 17 beneath the bearing as shown more clearly in Figures 1 and 3.

A pair of transverse I-beams 18 laid upon the spokes 14 support a platform 19 on which is mounted a power plant 20 enclosed in a housing 21. The power plant has a main or crank shaft 22 which lies longitudinally of the machine as shown in Figure 2. The platform 19 further supports a pair of upright Between the bearings 23 in which is journaled a transverse shaft 24. This shaft carries a bevel pinion 25 meshing with another pinion 26 on the shaft 22, whereby the shaft 24 is driven. The shaft 24 further carries a pair of drums 27 for winding a cable 28, and the drums are separately locked to the shaft by means of clutch devices 29 to be rotated thereby for winding the cable 28 in one direction or the other. This cable may be joined to certain mechanism carried by a boom pivoted to the forward edge of the platform 19 in the manner well known in the art and which need not be described in detail here.

The upper end of the hub 16 is concavely recessed as at 31 (Figure 1) at diametrically opposite points to support a countershaft 32 lying transversely of the machine. Opposite points on the ring structure 13 are similarly formed for the same purpose. The shaft carries a pair of loose bevel gears 33 meshing with the ring gear 11 at substantially opposite points thereof. The shaft however carries no appreciable weight inasmuch as the carriage 13 is supported on the track 12 by means of the rollers 15. Sprocket members 34 are fixed on the shaft 32 and are driven by chains 35 passing over sprockets 24 on the shaft 24.

The shaft 32 carries fixed clutch members 36 adapted to cooperate with clutch faces 37 provided for the gears 33-. It will be seen that the members 36 are spaced apart less than the. members 37, and the shaft 32 is rendered slidable by a lever 38, so that onlyone of the gears 33 may be locked to'the shaft at one time. By the selective clutching of these gears, the carriage 13 and the super structure thereon may readily be turned in one direction or the other.

The reduced portion 5 of each of the frames 1 carries a bearing 40 receiving one end of a stub shaft 41, the other end of the shaft being journalled in the bearing 42 fixed to the ring 8 at a point opposite the bearing 40. Each stub shaft carries a gear 43 with an associated sprocket wheel 44 which is geared by asprocket chain 45 to another wheel 46 on the corresponding shaft 2 at the forward end of the traction member, whereby the tread members 4 are geared to the gears 43. The shaft 32 carries a pair of gears 47 splined thereon and slidable for a short distance to engage or disengage the gears 43. Each gear 47 is provided with an operating lever 48 whereby its relation to the adjacent gear 43 is governed. It will be apparent that the machine may be propelled in a straight line by engaging both gears 47 with their respec- .tive gears. 43, and steered to one side or the other by engaging only. one of the gears. It will also be seen that the traction device is operated from the power plant as are the drum shaft 24. and countershaft 32.

In driving the gears 43 and hence the trace tion members from the gears 47, it is necessary to maintain the shaft 32 parallel to the transverse axis of the traction members or parallel to the stub shafts 40, in order to pre-.

vent one of the gears 47 from lagging behind the-other'under load. This is accomplished I by providing keepers 48 on the I-bea'ms 6, to

cooperate with a latch 49 carried by the ring 13. The latch is supported by a bell crank lever 50 pivoted to a lug 51 on the ring. An

operating link 52 extends from one end of the bell crank lever to a point within convenient reach of the operators station and the lower end of the latch is guided in an ear 53 carried by the ring. When the latch is received in either of the keepers 48, the ring is prevented from shifting and hence the shaft 32 is prevented from deviating from a position parallel to the transverse axis of the traction members. The provision of two keepers permits locking of the rin in this manner in positions 180 apart. he latch is entered into one of the keepers when the traction device is to be propelled, and is obviously released when the device is in service as an excavator to permit turning of the ring 13.

Although a specific embodiment of the invention has been illustrated and described, it will be understood that various alterations in the details of construction may be made without departing from the scope of the invention, as indicated by the appended claims.

What I claim is 1. In a portable machine, a traction device, a base structure supported thereby, a track and a ring gear mounted on said base structure, a carriage having rollers on said track, a power plant supported by said carriage, a countershaft journalled over said carriage, a pair of drive gears loose on said countershaft. and meshing with said ring gear at substantially diametrically opposite points, clutch mechanism on said countershaft for selectively locking said gears thereto, a pair of traction gears loose on said countershaft and geared to opposite sides of said traction device, and clutches for separately lockingsaid traction gears to said countershaft, whereby the machine may be steered.

. 2. In a portable machine, a pair of parallel traction devices, transverse members joining and sup'ported by said members, a base member supported by said transverse members and having a central bearing, a track and ring gear on said base member, a carriage having rollers on said track, a hub extending from said carriage into said bearing, a power plant supported by said carriage, a countershaft journalled on said huband transversely thereof, a pair of drive gears loose on said countershaft and meshing with said ring gear at substantially diametrically opposite points, and clutch mechanism on said coungears loose on said countershaft and meshing with said ring gear at substantially diametrically opposite points, clutch mechanism on said countershaft for selectively locking said gears thereto, gearing between said countershaft and traction device, and means for locking said carriage to said traction device.

a. in a portable machine, a pair of parallel traction devices, transverse members joining and supported by said members, a base member supported by said transverse members iand having a central bearing, a track and ring gear on said base member, a carriage having rollers on said track, a hub extending from said carriage intosaid bearing, a power plant supported by said carriage, a countershait't journalled over said carriage, a. pair of drive gears loose on said countershaft and meshing with said ring gear at substantially diametrically opposite points, clutch mechanism on said countershaft for selectively locking said gears thereto, a pair of traction gears loose on said countershaft and geared to opposite sides of said traction device, and clutches for separately locking said traction gears to said countershaft, whereby the machine may be steered.

5. In a portable machine, a pair of parallel traction devices, transverse members joining and supported by said members, a base member supported by said transverse members and having a central bearing, a track and ring gear on said base member, a carriage having rollers on said track, a hub extending from said carriage into said bearing, a power plant supported by said carriage, a countershaft journalled on said hub and transversely thereof, a pair of drive gears loose on said countershaft and meshing with said ring gear at substantially diametrically opposite points, clutch mechanism on said countershaft for selectively locking said gears thereto, a pair of traction gears loose on said countershaft and geared to opposite sides of said traction device, and clutches for separately locking said traction gears to said countershaft, whereby the machine may be steered.

In testimony whereof I afiix my si ature.

NORMAN A. WRI HT. 

